Corn syrups. Standard corn syrup is a water solution of glucose chains of varying lengths (left). One- and two-unit sugars taste sweet, while taste-free longer chains make the syrup viscous. By controlling the relative populations of different chains, the manufacturer can tailor the syrup’s balance of sweetening and thickening powers. High-fructose corn syrup (right) has been treated with an enzyme to convert a portion of the single glucose molecules (small hexagons) into fructose molecules (small pentagons), which taste sweeter.